A handful of services to which we are welded for huge amounts of time have made some fairly radical design alterations of late. Twitter, YouTube, Gmail have all introduced major revamps to their interfaces, causing much hand-wringing and consternation from vociferous users who are unclear as to why things couldn't be left as they were.

We tend to become short-sighted in such situations; it's possible – likely, even – that the changes represent improvement, but we resent having our behaviour modified. It's like turning up at work to find that the toilets and the cafeteria have been quietly moved to another part of the building, combined into one facility and relabelled as an Energising And Restorative Zone.

The changes are, largely, understandable and necessary. As services expand, features are added that can make them unwieldy, to a point where the complexity of the interface puts off new users. And in the words of Ryan Sarver, Twitter's director of platform, "when you're trying to simplify a product you have to make some tough decisions". In Twitter's case, the changes involve grouping its features under menu items called Connect and Discover; this may be more intuitive for those signing up for the first time, but there are millions of existing users clicking around in confusion and posting messages of complaint (when they've worked out how to do so).

Over at Gmail, the changes involve the dropping of the black menu bar (which was only introduced comparatively recently) and reducing the number of colours and lines; again, probably a sound design choice, but it does leave you feeling like one of those disappointed contestants after Laurence Llewelyn-Bowen wreaked havoc on Changing Rooms.

YouTube's changes seem the most obviously successful; the pop-up message says: "We've updated the homepage to make it easier to find and watch the videos that matter to you." And after a few minutes you begrudgingly admit that this may be right.

I used to find whining over interface changes to be predictable and irritating; my sympathy tended to lie with the developers who were merely trying to keep pace with technology and improve a site that, after all, we were all using free of charge. But every business model depends on happy customers, and change can be jarring. It'll be fascinating to see the reaction to Windows 8, which takes many cues from Windows Mobile and represents a massive shift in design. Some people will be furious – but is it the fault of designers for being insensitive, or ours for failing to understand their motives?

Still confused by computers? Maybe it's time to say hello to Alex

In retrospect, we should be grateful for improvements in OS design. Throughout the 1990s I remember Macs being jeered at by geeks for being too user friendly, but as computers take on an increasingly vital role in society, accessibility is crucial; user interfaces have to appeal to those who've found themselves on the wrong side of the digital divide.

One Linux-based laptop by the name of Alex is currently being touted for those "who feel confused and frustrated about computers" (which, without wishing to stereotype a generation, tends to mean the over-50s). A couple of years ago a system with similar aims called Simplicity was launched with Valerie Singleton as the figurehead, but it failed to make much impact. Alex now seeks to succeed where Valerie failed.

The system – the brainchild of former TV producer Andy Hudson – has been subjected to user testing against a Windows setup (although notably not against Macs) and 85 per cent of computer novices stated a preference for Alex. It's debatable whether the £399 price tag and the promise of stress-free computing will persuade the 20 per cent of the adult population without a computer to take the plunge; many of those people simply loathe technology and would gladly set about the contents of an electrical store with a cudgel in some re-enactment of a scene from the industrial revolution.

But over time – as tech-savvy kids grow older and computing power becomes cheaper, we can at least reassure ourselves that the digital divide will one day disappear.

A long way from @twelveangrymen– the perils of a tech-savvy jury

Last week the Arkansas Supreme Court overturned a murder conviction when it transpired that a juror had been tweeting his thoughts throughout the trial, such as "the coffee here sucks". The act of tweeting, texting or updating Facebook has become so impulsive and natural that we often fail to consider the consequences – and disrupting judicial procedures probably counts as among the most serious. The accused will now face a retrial, but you only need to scan Twitter to see that the practice is widespread.

Michael Bromby, a reader in the department of law at Glasgow Caledonian University, produced a short paper last year that studied the online behaviour of jurors who had just announced their imminent period of duty on Twitter. He turned up such classic goofs as: "Yay! Jury duty! That guy looks so guilty!" A search I did yesterday found similarly alarming stuff. "I'm too drunk to do jury duty," one said. Another said: "I got jury duty tomorrow – not guilty all da way unless u a did a crime against women and children." Obviously I welcome the lawful judgments of my peers, just as long as they're not: a) drunk; or b) stupid.

Who on earth are the 12 mobile-phone users who find SMS spam helpful?

My friend Jo turned on her new mobile phone last week to be greeted with the news that if she'd purchased mortgage insurance prior to a certain date, she may be entitled to compensation.

She didn't even know her own mobile number yet, but the sender of this spam SMS clearly did, whether by research or by guesswork.

The act of sending spam texts carries a potential £500,000 fine, but they still flood the networks, causing 95 per cent of us to experience "concern, inconvenience or distress" according to one survey.

The good news is that the Information Commissioner's Office has launched a crackdown on the practice, with one raid on a suspected offender taking place last week.

The bad news, however, emerges from between the lines of the same survey; of the 1,014 people interviewed, 12 said that the spam texts were "helpful".

It's these 12 confused people and other people like them across the world who ensure that these fishing practices turn out to be financially worthwhile for the perpetrators; it's certainly way more effective than email spamming, because text messages aren't filtered and tend to send people scurrying for their phones.

As ever, the best response is to delete them – or forward to the spam service on your network: 7726 (SPAM) for T-Mobile, Orange and O2; 87726 (VSPAM) for Vodafone; or 37726 (3SPAM) for 3. But whatever you do don't text back "STOP". You may as well text back "START".

Cyber Culture, Rhodri Marsden's monthly tech column returns on 12 January